As the global population surges and dietary preferences evolve, aquaculture stands out as one of the fastest-expanding sectors in food production. Yet, the rapid growth of this industry has sparked rising concerns regarding its environmental footprint, particularly the emission of greenhouse gases (GHGs). These emissions contribute to climate change, and while aquaculture offers a vital pathway to meet increasing protein demands, understanding and mitigating its carbon footprint has become paramount. The question arises: how substantial are the GHG emissions generated from fish, shrimp, and shellfish production, and what strategies exist to curtail them?
A recent comprehensive review by Professor Hong Yang of the University of Reading’s Department of Geography and Environmental Science dives deep into this subject. Synthesizing insights from 1,821 studies sourced from the Web of Science database, this work meticulously dissects the various origins of GHG emissions within aquaculture, differences across species, geographic emission trends, and practical mitigation pathways. Published in Frontiers of Agricultural Science and Engineering, this review builds a critical scientific foundation to guide the industry’s transition toward sustainability and lower carbon intensity.
The study identifies four primary stages responsible for GHG emissions in aquaculture systems: feed production, energy consumption during farming operations, biogeochemical reactions within aquatic environments, and land-use change linked to infrastructure development. Feed production emerges as the dominant emission source in most fed aquaculture systems, accounting for a staggering 52% of emissions in regions like China where such data is available. Concurrently, methane emissions from ponds and water bodies — stemming from anaerobic decomposition and other biogeochemical cycles — represent a significant fraction, especially in freshwater pond aquaculture. In some cases, methane can constitute up to 90% of the total emissions, underscoring its environmental significance.
Species type considerably influences the GHG footprint. Unfed bivalves, such as oysters and clams, along with seaweed farms, generally exhibit remarkably low or even negative carbon emissions. These systems not only have minimal direct emissions but can act as carbon sinks via mechanisms like carbon sequestration in biomass and sediments. Similarly, herbivorous and omnivorous fish species like carp and tilapia demonstrate moderate emissions, particularly under controlled farming intensities. Conversely, carnivorous fish such as salmon and trout, coupled with shrimp farming under intensive protocols, display elevated emission intensities. The reliance on energy-dense feeds and substantial energy inputs for these species often equates their carbon footprints to those of traditional terrestrial livestock.
Regional disparities in emissions reflect variations in production systems and geographic characteristics. China stands out as the world’s largest emitter from aquaculture activity, contributing over half of global GHG emissions in this sector. Asian countries like India, Indonesia, and Vietnam follow closely, characterized mainly by extensive pond farming methods that are prone to high methane emissions. In contrast, developed economies including Norway and Canada report lower aggregate emissions but face higher carbon intensities per production unit. This reflects their energy-intensive farming technologies—such as recirculating aquaculture systems—and the carbon costs associated with long-distance transportation.
Mitigating GHG emissions in aquaculture demands multifaceted approaches, several of which show promise at various stages of production. Enhancing feed formulations to increase nutrient assimilation efficiency can drastically reduce emissions attributed to feed production. Employing renewable energy sources and improving energy efficiency during farming operations also cut direct emissions significantly. Furthermore, optimizing water and waste management, incorporating integrated multi-trophic aquaculture (IMTA), and rehabilitating blue carbon ecosystems—such as mangroves—provide ecosystem-based benefits that reduce methane and nitrous oxide emissions from aquatic environments.
Importantly, the review stresses that aquaculture’s overall carbon footprint is not inherently high across the board. Instead, it varies considerably, hinging on species selection, farming methods, regional practices, and technological innovation. As such, rather than portraying the industry monolithically, the study advocates nuanced, evidence-based strategies tailored to specific contexts. This perspective aligns with global climate goals by fostering a low-carbon transformation that sustains food security while mitigating environmental risks.
The role of technological innovation also stands central to achieving these objectives. Advances in feed ingredient sourcing, including alternative proteins such as insect meal and single-cell proteins, offer promising avenues to replace carbon-intensive conventional feeds. Precision aquaculture technologies, including sensors and automated systems, can optimize resource use and lower energy consumption. Additionally, genetic improvements targeting feed conversion ratios and disease resistance in cultured species may further reduce GHG intensities.
Policy frameworks and industry collaboration emerge as pivotal enablers for driving widespread adoption of sustainable best practices. Regulatory incentives aimed at promoting renewable energy adoption, carbon accounting mechanisms tailored for aquaculture, and international knowledge-sharing platforms can accelerate progress toward decarbonization. Consumer awareness and market dynamics also play influential roles, as demand for eco-labeled seafood grows and encourages producers to minimize environmental footprints.
In essence, the aquaculture sector is at a crossroads. It must balance its critical role in feeding a burgeoning global population against the imperatives of climate change mitigation. Professor Yang’s comprehensive review illuminates a path forward grounded in scientific rigor, highlighting that with targeted interventions, the industry can evolve into a more sustainable and climate-resilient contributor to global food systems. This transformation not only aligns with environmental stewardship but promises economic and social benefits across diverse producer communities worldwide.
The findings emphasize that addressing GHG emissions in aquaculture requires integrated approaches that span production, environmental management, technology, and policy. By focusing on low-impact species, optimizing feed and energy use, enhancing ecosystem services, and fostering innovation, aquaculture can significantly reduce its climate burden. This multi-dimensional strategy underscores a hopeful future where aquaculture supports both global nutrition security and global climate ambitions harmoniously.
As the industry moves forward, continuous monitoring, research, and adaptive management will be essential to track progress and refine best practices. Collaboration between scientists, producers, policymakers, and consumers will collectively shape the trajectory toward a low-carbon aquaculture paradigm. The insights presented in this review constitute a timely and vital contribution, guiding stakeholders through the complexities of emission sources, regional peculiarities, and sustainable alternatives on an unparalleled scale.
By articulating the nuanced environmental challenges and offering a robust framework for mitigation, this work stands as a landmark in the quest for responsible aquaculture. Through informed decision-making and committed action, the sector can fulfill its promise of nourishing the world while safeguarding planetary health for generations to come.
Subject of Research: Not applicable
Article Title: Understanding and mitigating greenhouse gas emissions in aquaculture: a review of emission sources, regional trends and sustainability pathways
News Publication Date: 15-Jun-2026
Web References:
DOI: 10.15302/J-FASE-2025665
Image Credits: HIGHER EDUCATION PRESS
Keywords: Aquaculture, Greenhouse Gas Emissions, Methane, Nitrous Oxide, Feed Production, Carbon Footprint, Sustainability, Aquatic Farming, Carbon Sequestration, Integrated Multi-Trophic Aquaculture, Blue Carbon Ecosystems, Renewable Energy
